Special Vertical & Lateral Load Considerations for Steel Joists & Joist Girders


Matthew Stuart, P.E., S.E., F.ASCE


Course Outline

This one hour online course will provide the user with an understanding of the special design considerations necessary when dealing with unusual vertical and horizontal loads on steel joists and joist girders. This course includes a multiple choice quiz at the end.

Learning Objective

At the conclusion of this course, the student will:

Course Introduction

Often in the course of the design of a joist, loads in addition to uniform vertical gravity loads are imposed on the member. In such a situation, for an engineer to be able to select the appropriate member size or specify the correct load resisting performance of a joist, the designer must be able to properly interpret the manufacturer's allowable load tables and member capacities for both shear and moment. This course will guide the engineer through that process.

The design of the overall stability of a building involves an understanding of the load-path mechanism that distributes the imposed wind or seismic loads from the cladding to the foundations. Steel joists and joist girders are limited in this regard. This course will help guide the engineer through the understanding of what these limitations are.

Course Content

The course content is contained in the following PDF file:

Special Vertical & Lateral Load Considerations for Steel Joists & Joist Girders

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

If you have trouble reading any of the material on line, it is recommended that the course material be printed out for better resolution.

Course Summary

The designer must compensate for non-uniform loads on joists by developing the shear and moment diagram for a particular member in order to establish an equivalent uniform load for use in selecting a standard joist or specify a KCS series joist. A third alternative involves the development of a loading diagram to enable the joist manufacturer to design and fabricate a special joist for each load case.

Lateral diaphragm collector and chord forces must be transmitted between the metal deck and the lateral resisting system via the joist or joist girder member chords. Standard joists and joist girders have limited capacities available to accomplish this goal. Special detailing provisions may be required when the member bearing seat assembly is not capable of transferring the magnitude lateral loads involved.

Additional Resource

You can download a program from Vulcraft's website called Vulcraft Assistant that helps you design joists with concentrated loads (http://www.vulcraft-in.com/). The program does not do any deflection calculations.

Related Links

For additional technical informaion related to this subject, please visit the following websites or web pages:

Steel Joist Institute
Vulcraft
Ten Situations to Avoid when Designing with Steel Joists
Up on the rooftop: How to design and detail non-uniform loads on steel joists


Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz


DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.org or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.